We can plan for the future by studying the past.

Marine resource management decisions are often made through
processes that are not based explicitly on resource data &mldr;
important weaknesses in current decision-making processes
involve two issues that spatial tools can help address: public
participation and the availability of data and information.

The most pressing management decisions revolve around
climate change and the associated changes in environmental
conditions coupled with increasing industrial development and
consequent human uses of the ocean and near shore
environments.

For the first time, you can simultaneously view multiple sources of historical sea
ice data from the oceans surrounding northern
Alaska. Choose a region and time of interest and inspect a map of data collected
between the mid-1800s and today,
to discover how ice extent and concentration have changed over time.

If you are a resident of a coastal community,
someone who hunts or fishes in a marine environment, a member of
the shipping or oil + gas industries, in the US Coast guard, a
scientist, or otherwise interested in Arctic sea ice data and
climate change, this atlas is for you.

Data considerations

These data show “snapshots” in time, as well as historical
trends in arctic sea ice cover and extent. They are not projections
or predictions of future conditions.
The atlas is not designed for forecasting or prediction, but can provide
useful historical context for future planning efforts.

Factors that create uncertainty in these data

Data collection challenges. Collecting sea ice data has always been difficult and dangerous work.
Historic interpretations of ice
concentration differed from modern protocols. A wide variety of instrument calibrations
and sensors (human observation, radar, satellites) has been used over time.
All add up to data inconsistencies.

Data compilation choices. Compiling data involves choices: Which hard copy maps to digitize? How do
we interpret this handwriting? How do we fill gaps in the data
record? Which time scale is best to use?
These choices lead to uncertainty.

Sources of monthly sea ice data used in this atlas

Alphabetical listing of data sources

Analog filling of spatial and temporal gaps: Spatial and temporal gaps in a given grid filled with best analog representations of the given month.

Arctic and Antarctic Research Institute (AARI) Located in St. Petersburg, Russia, AARI produces sea ice charts for safety of navigation in the Eurasian Arctic
and other operational and scientific purposes. Chart coverage focuses on the Northern Sea Route, although later
charts extend into the central Arctic. Charts contain several categories of ice concentration.

Japan Meteorological Agency Monitors sea ice in the Sea of Okhotsk from November to July. Results of monitoring are published for public use.

Kelly ice extent grids Digitized ice edge information from monthly maps of Danish Meteorological Institute, May-Sept only.
Kelly digitized only the inferred ice edge and only to a spatial resolution of about 100 km, depending
on the distance of the ice boundary to the pole. He chose not to improve the resolution because of the
low accuracy of the inferred ice edge itself. The eventual plan was for this digitized data to be
incorporated on a one-degree grid into larger sea ice data products as an ice/no ice indicator.

Naval Oceanographic Office (NAVOCEANO) Oversees the Naval Ice Center (NAVICE), which provides worldwide operational ice analyses for the US military
and government agencies as well as allied nations. Sea ice maps for the Alaskan and Greenland sectors were compiled
into yearbooks for the period 1953–1971. Hard copies of yearbooks are held by the National Snow and Ice Data Center (NSIDC). In 1972, ice charting was transitioned to the predecessor of the National Ice Center.

Navy-NOAA Joint Ice Center Climatology The National Ice Center began in 1976 as the Joint Ice Center in 1976, comprised of personnel from NOAA
and the US Navy. In 1995, the Joint Ice Center became the National Ice Center as it expanded to include
the US Coast Guard. Coast Guard aircraft, icebreakers, and Marine Safety Offices contribute valuable platforms
for onsite aerial and ship observations, as well as accurate and timely ship and station reports.
Ice charts dating back to 1972 are from predecessor organization. Hard-copy (paper) charts produced by analysts
are subsequently scanned and digitized. Ice charts are based mainly on satellite imagery, supplemented by aircraft,
ship and shore reports.

NSIDC SMMR/SSMI/AMSR microwavew sensor data Three separate microwave sensors. AMSR-E is the latest sensor, improving upon past microwave radiometers
SSM/I and SMMR. The spatial resolution of AMSR-E data doubles that of Scanning Multichannel Microwave
Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) data. Also, AMSR-E combines into one
sensor all the channels that SMMR and SSM/I had individually.

Walsh and Johnson/Navy-NOAA Joint Ice Center Early version of pan-Arctic digital database of Arctic sea ice concentrations. Grids cover the pre-satellite
(passive microwave) period and are synthesized from various sources. Resolution is 60 nautical miles in space and monthly in time. Described in: Walsh and Johnson, 1979, J. Phys. Oceanography, 9, 58–591.

Whaling ship logbook data Daily observations taken from logbooks and journals of whaling vessels cruising in the Bering and Chukchi
seas to investigate seaice conditions in this region of the Arctic between 1850 and 1914.
Extracted and digitized daily data on the presence or absence of sea ice from logbook records of annual
cruises in an unbroken record from 1850 to 1914, though there were very few cruises (hence inadequate
data) from 1911 to 1914. Data include more than 52,000 daily observations in an unbroken 65 year record
from 516 cruises. These represent 19% of the total 2,712 cruises.
Similar findings are discussed by Eicken et al. in this paper.

A joint project funded by the Alaska Ocean Observing System (AOOS), the Alaska Center for Climate Assessment and Policy (ACCAP),
and the Scenarios Network for Alaska and Arctic Planning (SNAP)

Partners. Funded by the National Ocean Service at the
National Oceanic and Atmospheric Administration (NOAA) through AOOS grant &num;NA11NOS0120020.
Work was performed at UAF by the International Arctic Research Center's ACCAP (funded by the NOAA Office of Oceanic and Atmospheric Research) and SNAP, with assistance from the University of Illinois, Urbana-Champaign.